U.S. patent application number 12/937849 was filed with the patent office on 2011-02-24 for large scale process for polymerization of dapbi-containing polyaramid.
Invention is credited to Richard Elena Theodorus Petrus De Vos, Marlieke Elisabeth Josephine Pepels, Joannes Marinus Surquin.
Application Number | 20110046340 12/937849 |
Document ID | / |
Family ID | 39512495 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110046340 |
Kind Code |
A1 |
De Vos; Richard Elena Theodorus
Petrus ; et al. |
February 24, 2011 |
LARGE SCALE PROCESS FOR POLYMERIZATION OF DAPBI-CONTAINING
POLYARAMID
Abstract
A method for obtaining an aromatic polyamide crumb from an
aromatic diamine and an aromatic diacid chloride, which aromatic
polyamide comprises 5(6)-amino-2-(p-aminophenyl)benzimidazole
terephthalamide units and has a relative viscosity .eta..sub.rel of
at least 3, by: (1) adding at least monomers (i)-(iii) in N-methyl
pyrrolidone as solvent wherein (i) is 0-30 mole %
para-phenylenediamine (PPD), (ii) is 20-50 mole %
5(6)-amino-2-(p-aminophenyl)benzimidazole (DABPI), (iii) is
49.05-50.05 mole % terephthaloyl dichloride (TDC), and optionally
calcium chloride to obtain a CaCl.sub.2/aromatic diamine molar
ratio less than 0.5, and an aromatic diamine/aromatic diacid
chloride ratio between 0.99 and 1.01; (2) mixing the monomers and
the optional calcium chloride to a homogenous mixture having a
monomer concentration of 5 to 12 wt %; followed by (3) adding
calcium chloride to the homogeneous mixture to obtain a
CaCl.sub.2/aromatic diamine molar ratio 0.6-1.0; and (4)
polymerizing the mixture.
Inventors: |
De Vos; Richard Elena Theodorus
Petrus; (Arnhem, NL) ; Surquin; Joannes Marinus;
(Arnhem, NL) ; Pepels; Marlieke Elisabeth Josephine;
(Nijmegen, NL) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Family ID: |
39512495 |
Appl. No.: |
12/937849 |
Filed: |
April 9, 2009 |
PCT Filed: |
April 9, 2009 |
PCT NO: |
PCT/EP09/54277 |
371 Date: |
October 14, 2010 |
Current U.S.
Class: |
528/372 |
Current CPC
Class: |
C08G 73/18 20130101;
C08G 69/32 20130101; C08G 69/28 20130101; C08K 3/16 20130101 |
Class at
Publication: |
528/372 |
International
Class: |
C08G 73/18 20060101
C08G073/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 2008 |
EP |
08007566.6 |
Claims
1. A method for obtaining an aromatic polyamide crumb from an
aromatic diamine and an aromatic diacid chloride, which aromatic
polyamide comprises 5(6)-amino-2-(p-aminophenyl)benzimidazole
terephthalamide units and has a relative viscosity .eta..sup.rel of
at least 3, comprising: adding at least monomers (i)-(iii) in
N-methyl pyrrolidone as solvent wherein: i) is 0-30 mole %
para-phenylenediamine (PPD); ii) is 20-50 mole %
5(6)-amino-2-(p-aminophenyl)benzimidazole (DABPI); iii) is
49.05-50.05 mole % terephthaloyl dichloride (TDC); and optionally
calcium chloride to obtain a CaCl.sub.2/aromatic diamine molar
ratio less than 0.5, and an aromatic diamine/aromatic diacid
chloride ratio between 0.99 and 1.01; mixing the monomers and the
optional calcium chloride to a homogeneous mixture having a monomer
concentration of 5 to 12 wt %, followed by adding calcium chloride
to the homogeneous mixture to obtain a CaCl.sub.2/aromatic diamine
molar ratio 0.6-1.0; and polymerizing the mixture.
2. The method according to claim 1 wherein the CaCl.sub.2/aromatic
diamine molar ratio in the homogeneous mixture is 0.65-0.85
3. The method according to claim 2 wherein the CaCl.sub.2/aromatic
diamine molar ratio in the homogeneous mixture is 0.70-0.80.
4. The method according to claim 1 wherein first the aromatic
diamines are mixed for 1 to 180 min in N-methyl pyrrolidone wherein
the CaCl.sub.2/aromatic diamine molar ratio is 0, after which the
aromatic diacid chlorides are added and mixed for another 1 to 180
min followed by adding calcium chloride to obtain a
CaCl.sub.2/aromatic diamine molar ratio 0.6-1.0.
5. The method according to claim 1 wherein calcium chloride is
added as an NMP/CaCl.sub.2 mixture.
6. The method according to claim 1 which is performed in a reactor
having a measure capacity of at least 50 L.
7. The method according to claim 1 which is performed in a
cylindrical reactor having a measure capacity of at least 50 L
which is equipped with a single mixing gear for use as stirrer and
granulator.
8. The method according to claim 1, wherein first the aromatic
diamines are mixed for 3-30 min in N-methyl pyrrolidone wherein the
CaCl.sub.2/aromatic diamine molar ratio is 0, after which the
aromatic diacid chlorides are added and mixed for another 3-30 min,
followed by adding calcium chloride to obtain a CaCl.sub.2/aromatic
diamine molar ratio of 0.6-1.0.
9. A method for obtaining an aromatic polyamide crumb from an
aromatic diamine and an aromatic diacid chloride, which aromatic
polyamide comprises 5(6)-amino-2-(p-aminophenyl)benzimidazole
terephthalamide units and has a relative viscosity .eta..sub.rel of
at least 3, by adding at least monomers (i)-(iii) in N-methyl
pyrrolidone as solvent wherein: i) is 0-30 mole %
para-phenylenediamine (PPD); ii) is 20-50 mole %
5(6)-amino-2-(p-aminophenyl)benzimidazole (DABPI); iii) is
49.05-50.05 mole % terephthaloyl dichloride (TDC); and optionally
calcium chloride to obtain a CaCl.sub.2/aromatic diamine molar
ratio less than 0.5, and an aromatic diamine/aromatic diacid
chloride ratio between 0.99 and 1.01; mixing the monomers and the
optional calcium chloride to a homogeneous mixture having a monomer
concentration of 5 to 12 wt %, followed by adding calcium chloride
to the homogeneous mixture to obtain a CaCl.sub.2/aromatic diamine
molar ratio 0.6-1.0; and polymerizing the mixture.
10. The method according to claim 1 wherein the CaCl.sub.2/aromatic
diamine molar ratio in the homogeneous mixture is 0.65-0.85
11. The method according to claim 2 wherein the CaCl.sub.2/aromatic
diamine molar ratio in the homogeneous mixture is 0.70-0.80.
12. The method according to any one of claims 1 to 3 wherein first
the aromatic diamines are mixed for 1 to 180 min, preferably for
3-30 min, in N-methyl pyrrolidone wherein the CaCl.sub.2/aromatic
diamine molar ratio is 0, after which the aromatic diacid chlorides
are added and mixed for another 1 to 180 min, preferably for 3-30
min, followed by adding calcium chloride to obtain a
CaCl.sub.2/aromatic diamine molar ratio 0.6-1.0.
13. The method according to any one of claims 1-4 wherein calcium
chloride is added as an NMP/CaCl.sub.2 mixture.
14. The method according to any one of claims 1-5 which is
performed in a reactor having a measure capacity of at least 50
L.
15. The method according to any one of claims 1-6 which is
performed in a cylindrical reactor having a measure capacity of at
least 50 L which is equipped with a single mixing gear for use as
stirrer and granulator.
Description
BACKGROUND
[0001] The invention relates to a method for obtaining a
composition in the form of a crumb comprising an aromatic polyamide
from an aromatic diamine and an aromatic diacid chloride, which
aromatic polyamide comprises
5(6)-amino-2-(p-aminophenyl)benzimidazole terephthalamide units and
has a relative viscosity .eta..sub.rel of at least 3 by
copolymerizing 5(6)-amino-2-(p-aminophenyl)benzimidazole (DAPBI)
and optionally para-phenylenediamine (PPD), and terephthaloyl
dichloride (TDC) in a mixture of N-methyl pyrrolidone (NMP) and
calcium chloride.
[0002] A method of adding calcium chloride to a solvent in a
polymerization mixture or after the start of the polymerization
process is known from U.S. Pat. No. 4,172,938. This reference
discloses in example 34 the polymerization of a PPD/DABPI/TDC
mixture. However, according to this reference all of the calcium
chloride was added in the NMP solvent prior to adding the monomers.
Further a low DABPI content (10 mole %) polymer was made. This
process did not lead to the forming of a crumb, but only a
paste-like product was obtained. This reference does further not
give any hint that all calcium chloride can be added after having
added the monomers to the solution, and when part of the calcium
chloride is added after the start of the polymerization process,
the CaCl.sub.2/aromatic diamine molar ratio must become 0.6-1.0 to
obtain crumb.
[0003] A method for performing such polymerization reaction but
obtaining a composition in the form of a crumb or a crumb-like
material was disclosed in WO 2005/054337. According to this method
the monomer of interest, DAPBI
(5(6)-amino-2-(p-aminophenyl)-benzimidazole), is added to the
aromatic diamine mixture with the objective to obtain a suitable
polymer solution right after polymerization with e.g. PPD and TDC,
which can be directly shaped into fibers or films, whereby DAPBI is
seen as a suitable co-monomer to keep the aramid polymer in
solution. It was found that by selecting a specific molar ratio of
PPD, DAPBI, and CaCl.sub.2 the formation of powders, paste, dough,
and the like could be prevented. Said method therefore pertains to
a method for obtaining an aromatic polyamide comprising
5(6)-amino-2-(p-aminophenyl)benzimidazole terephthalamide units as
a crumb with a relative viscosity .eta..sub.rel of at least 4.
[0004] This method, wherein the monomers are added to the final
solvent system (CaCl.sub.2/NMP) is very suitable for obtaining
crumbs and crumb-like materials when performed at the scale as
indicated in this patent application, i.e. in a small reaction
flask of 2 L.
[0005] Unfortunately, it appeared that this method failed when the
process was scaled-up. Thus under commercial production conditions
in a reactor having a capacity of larger than 50 L, such as in a
Drais reactor of 160 L, no crumbs were formed and the material was
obtained as a big lump sticking around the stirrer, which was not
suitable for further processing. It is therefore an object of the
invention to provide a method that is suitable for large scale
production for obtaining aramid polymer having DAPBI units with a
high relative viscosity and a suitable material consistency. The
method of course can also be used for small-scale production of
aramid polymer having DAPBI units. When used for such small-scale
polymerization reactions the method of the invention can be
considered an alternative for the method of WO 2005/054337, wherein
the solvent is added prior to polymerization.
SUMMARY
[0006] To this end a method was found that relieved the problems of
the prior art method. Thus the invention pertains now to a method
for obtaining an aromatic polyamide crumb from an aromatic diamine
and an aromatic diacid chloride, which aromatic polyamide comprises
5(6)-amino-2-(p-aminophenyl)benzimidazole terephthalamide units and
has a relative viscosity .eta..sub.rel of at least 3, by
[0007] adding at least monomers (i)-(iii) in N-methyl pyrrolidone
as solvent wherein: [0008] i) is 0-30 mole % para-phenylenediamine
(PPD); [0009] ii) is 20-50 mole %
5(6)-amino-2-(p-aminophenyl)benzimidazole (DABPI); [0010] iii) is
49.05-50.05 mole % terephthaloyl dichloride (TDC); and optionally
calcium chloride to obtain a CaCl.sub.2/aromatic diamine molar
ratio less than 0.5, and an aromatic diamine/aromatic diacid
chloride ratio between 0.99 and 1.01;
[0011] mixing the monomers and the optional calcium chloride to a
homogeneous mixture having a monomer concentration of 5 to 12 wt %,
followed by
[0012] adding calcium chloride to the homogeneous mixture to obtain
a CaCl.sub.2/aromatic diamine molar ratio 0.6-1.0; and
[0013] polymerizing the mixture.
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] The thus obtained crumb material after coagulation and
washing with water followed by optionally drying is suitable for
making a spin dope by dissolving it in a solvent, for instance
sulfuric acid, NMP, NMP/CaCl.sub.2, N-methyl acetamide, and the
like. The dope can be used to manufacture formed articles, such as
fibers, films, and the like.
[0015] The term crumb or crumb-like as used in this invention means
that the polymer in the mixture after polymerization is fully or
substantially fully in the form of breakable clumps or particles,
which are not sticky (i.e. do not form a lump around stirrer), and
have a mean particle size greater than 100 .mu.m, usually greater
than 1 mm. See also the definition of crumbs for PPTA aramid in
Encyclopedia of Polymer Science and Technology, Vol. 3, page 565
(John Wiley & Sons) wherein PPTA crumbs are defined as
particles with the consistency of wet sawdust.
[0016] According to a preferred embodiment of the invention the
CaCl.sub.2/aromatic diamine molar ratio in the homogeneous mixture
is 0.6-1.0, preferably 0.70-0.80.
[0017] It is essential that the amount of calcium chloride reaches
the claimed molar ratio after the monomers have been homogenized in
the solvent. However, small amounts of calcium chloride may be
added prior to or during mixing the monomers before being
homogenized, for instance one or more of the monomers can be added
to the solvent NMP (N-methyl pyrrolidone) and calcium chloride, as
long as the molar ratio CaCl.sub.2/aromatic diamine is less than
0.5, i.e. between 0 and 0.5. The remainder of the calcium chloride
to obtain a ratio between 0.6 and 1.0 is then added after the
monomers have been homogenized in the solvent, preferably as a
mixture of calcium chloride and NMP. In a preferred embodiment, no
calcium chloride is present in the solvent to dissolve the monomers
and the calcium chloride is only added to the homogeneous mixture,
preferably as NMP/CaCl.sub.2 mixture. This method of adding calcium
chloride is quite unusual because the NMP/CaCl.sub.2 mixture is the
solvent (i.e. CaCl.sub.2 adds to the dissolving power of NMP) and
an activator for the polymerization reaction. There is no obvious
reason or expectation that the reaction would render a different
product if the calcium chloride is added in a later phase of the
process, i.e. that it renders a crumb whereas no crumb is formed
when the calcium chloride is immediately added at the start of the
polymerization reaction.
[0018] Thus embodiments of the invention are first mixing the
aromatic diamines including DABPI in N-methyl pyrrolidone to a
CaCl.sub.2/aromatic diamine molar ratio of 0, for 1 to 180 min,
preferably for 3-30 min, after which TDC is added and mixed for
another 1 to 180 min, preferably for 3-30 min, followed by adding
calcium chloride to obtain a CaCl.sub.2/aromatic diamine molar
ratio 0.6-1.0.
[0019] The monomer concentration in the solvent should be 5 to 12
wt % in order to obtain crumbs. The optimum concentration depends
on the DABPI content of the monomer mixture, but can easily be
determined by the artisan. As a rule of thumb, the higher the DABPI
content, the lower the monomer concentration in the solvent.
[0020] The aromatic diamines include DABPI. Optionally up to 30
mole % PPD is added as another monomer, but aromatic diamine
monomers such as para-chlorophenylene-diamine (Cl-PPD) and
para-methylphenylenediamine (Me-PPD) may also be added.
[0021] The aromatic diacid chloride include TDC, but small amounts
(up to 1.2 mole %) of other aromatic diacid chlorides may be
present.
[0022] The term "mole %" relates to the molar percentage of the
monomers with regard to the total of aromatic diamine and aromatic
diacid chloride monomers.
[0023] The terms "homogeneous mixture" and "homogenized" mean that
the monomers are homogeneously distributed in the solvent as a
solution, emulsion, or suspension.
[0024] When the monomers are homogenized calcium chloride is added
to obtain the required molar ratio. Calcium chloride can be added
as such or as a mixture, dispersion or solution, such as in the
form of an NMP/CaCl.sub.2 mixture.
[0025] The method is particularly suitable for commercial large
scale production of polymer as a crumb. Said large scale processes
are usually performed in reactors of a capacity of at least 50 L,
usually much bigger, for instance in reactors of 2500 L to 10.000
L, such as disclosed in EP 0743964.
[0026] The method is particularly suitable for use in a cylindrical
reactor having a measure capacity of at least 50 L which is
equipped with a single mixing gear used as stirrer and granulator,
such as is the case for the Turbulent-Schnellmischer mit
Flugelmischwerk of Drais. The method can also be used in a
continuous process.
[0027] Several batches of polyaramid with 20-50 mol % DAPBI were
prepared in a 160 L and 2500 L Drais reactor and showed good
reproducibility. Copolymers with relative viscosities above 4 were
found to be suitable for spinning yarns.
[0028] Generally the process of the invention comprises the
steps:
[0029] Adding solvent NMP in the reactor;
[0030] Adding PPD and DAPBI (and mixing from 1 to 180 min,
preferably 3-30 min);
[0031] Cooling to about 5.degree. C.;
[0032] Adding TDC (and mixing from 1 to 180 min, preferably 3-30
min);
[0033] Adding NMP/CaCl.sub.2 (to a CaCl.sub.2/(PPD+DAPBI) molar
ratio 0.6-1.0, preferably 0.70-0.80).
[0034] After about 15 minutes to 2 hours the polymer obtained has a
.eta..sub.rel of at least 3.
[0035] In the following experiments, the aspects of the invention
are exemplified.
EXAMPLES
General Polymerization Procedure
[0036] Materials:
DAPBI, 5(6)-amino-2-(p-aminophenyl)benzimidazole, melting
point=235.degree. C., purity>99.9% PPD (p-phenylenediamine),
melting point=140.degree. C., purity>99.9%, ex Teijin Aramid TDC
(terephthaloyl dichloride), melting point=80 .degree. C.,
purity>99.9%, ex Teijin Aramid NMP/CaCl.sub.2 and NMP (water
content<200 ppm), ex Teijin Aramid
[0037] Standard Teijin Aramid (Twaron.RTM.) polymerization methods
for making a copolymer with 20-50 mole % DAPBI containing an
overall copolymer composition of 50 mole % TDC, 15-35 mole % PPD
and 35-15 mole % DAPBI.
[0038] After polymerization the formed reaction product was
coagulated, washed with demineralized water and dried in a fluid
bed dryer (at 150.degree. C.).
[0039] Indicative for the quality of the formed polyaramid with
DAPBI units is the relative viscosity (.eta..sub.rel). The relative
viscosity is defined as the viscosity ratio of a 0.25 wt %
polyaramid solution in 96% H.sub.2SO.sub.4 to the polymer-free
solvent (96% H.sub.2SO.sub.4). This ratio is determined with a
capillary viscometer (Ubelohde) at 25.degree. C.
Results
Example 1
[0040] Preparation of Polyaramid with 35 mole % DAPBI Units
[0041] NMP and the amines (PPD and DAPBI) were mixed in a
horizontal cylindrical paddle mixer of Drais having a measure
capacity of 160 liter for 30 min and the mixture was cooled to a
temperature of 5.degree. C. and TDC was added. After cooling the
mixture to 5.degree. C., NMP/CaCl.sub.2 was added to obtain a
CaCl.sub.2/(PPD+DAPBI) molar ratio of 0.72. After one hour of
reaction time the reaction product consisting of small crumb-like
particles with a relative viscosity of 13.6, was obtained.
Polymerization without CaCl.sub.2 in the solvent resulted in
PPTA-DAPBI powder with .eta..sub.rel of maximum 1.2 (comparison;
Table 1).
Example 2
[0042] Polyaramid was prepared according to the method of Example
1, using 25 mole % rather than 35 mole % DAPBI units.
[0043] As comparison prior art examples for making aramid
copolymers were performed using 25 and 35 mole % DAPBI and various
monomer concentrations according to the method of WO
2005/054337.
[0044] Table 1 shows that the examples of the invention render
crumbs, whereas the prior art method leads to lumps that stuck
around the stirrer.
Example 3
[0045] Polyaramid with 25 mole % DAPBI units was prepared in a
`Turbulent-Schnellmischer mit Flugelmischwerk` Drais reactor with a
measure capacity of 2500 L.
[0046] To 897 L of NMP were added 11.99 Kg of PPD and 24.87 Kg of
DAPBI and this was mixed for 60 minutes. Subsequently, the mixture
was cooled to 5.degree. C. and 45.08 Kg of TDC (solid) were added
and mixed for 66 minutes at 50 RPM. To the mixture 145L of
NMP/CaCl.sub.2 (with 10.2 wt % CaCl.sub.2) were added and the
reaction proceeded at a stirrer speed of 160 RPM for 125 minutes.
The crumb-like reaction product was coagulated and washed with
demineralized water. After drying the relative viscosity of the
resulting DAPBI copolymer was 5.1.
Example 4
[0047] Preparation of Polyaramid with 25 mole % DAPBI Units
[0048] NMP/CaCl.sub.2 and the amines (PPD and DAPBI) with a
CaCl.sub.2/(PPD+DAPBI) molar ratio of 0.30 were mixed in a
horizontal cylindrical paddle mixer of Drais having a measure
capacity of 160 liter for 30 min and the mixture was cooled to a
temperature of 5.degree. C. and TDC was added. After cooling the
mixture to 5.degree. C., NMP/CaCl.sub.2 was added to obtain a
CaCl.sub.2/(PPD+DAPBI) molar ratio of 0.71. After one hour of
reaction time the reaction product consisting of small crumb-like
particles with a relative viscosity of 7.1, was obtained.
TABLE-US-00001 TABLE 1 Formulations of charges molar ratio
CaCl.sub.2/ Mono- Consistency Mole % (PPD + DAP mers Reaction Ex
Method DAPBI BI) (wt %) .eta..sub.rel product comparison 35 0 6.2
1.2 powder prior art* 35 0.76 12.4 4.2 lump around stirrer prior
art* 35 0.77 6.2 6.3 lump around stirrer prior art* 25 0.76 7.2 6.2
lump around stirrer 1 invention 35 0.72 6.2 13.6 Crumbs 2 invention
25 0.76 7.2 5.3 Crumbs 3 invention 25 0.70 7.0 5.1 Crumbs 4
invention 25 0.71 7.3 7.1 Crumbs *Method according to WO
2005/054337 wherein the solvent NMP/Cl.sub.2 was added prior to
polymerization
* * * * *